The nisi period is waiting period, during which spouses are not free to marry because they are still legally married to each other.
In most states divorce decrees are final when issued. Only four states now grant interlocutory judgments in divorce. They are California, Massachusetts and Nebraska, six months, and Utah, three months.
During the nisi period, a separation agreement waives it.
In uncontested divorces, the interlocutory period has been abolished.